Continuous casting apparatus



NOV. 5, 1968 J, clOcHETTO 3,409,070

CONTINUOUS CASTING APPARATUS Filed Aug 5 1966 5 Sheets-Sheet l Q "'3 "'3 Q R x INVENTOR- Q 4 J05EPH J. 6/00/5770 BY i 2 Nov. 5, 1968 J. J. CIOCHETTO 3,409,070

CONTINUOUS CASTING APPARATUS Filed Aug .5, 1966 5 Sheets-Sheet 2 INV EN TOR. JOSEPH J C/0CHETTO Nov. 5, 1968 .1. J. CIOCHETTO CONTINUOUS CASTING APPARATUS 5 Sheets-Sheet 5 Filed Aug.

0 A 3 mm V/ N 3 0 6 M n F m, a "T 5 5 7 J p T 8 MM x -1 v? u JEW H 7 1 l I 1| Pr United States Patent Oflice Patented Nov. 5, 1968 CONTINUOUS CASTING APPARATUS Joseph J. Ciochetto, Allison Park, Pa., assignor toKoppers Company, Inc., a corporation of Delaware Filed Aug. 5, 1966, Ser. No. 570,630

Claims. (Cl. 164-261) This invention relates to continuous metal casting and more particularly to an improved arcuate continuous casting mold oscillating apparatus.

When molten metal is poured into a cooled casting mold during a continuous casting operation, the metal solidifies first in the marginal zones adjacent thecool mold walls, and forms a solid skin around a molten metal core. To

prevent the solid skin from sticking to the walls of the mold, the mold customarily is oscillated upward and downward in a cyclical manner.

Various apparatus have been used heretofore for reciprocating the mold. One apparatus, used with a conventional vertical casting mold, includes cams and springs to move the mold downward and return the mold to the initial top position. Another apparatus, associated with the curved type of mold, includes a lever, pivotally mounted along its length, that is connected at one end to the mold and at the other end to a drive mechanism.-

The feature of a lever connected to the mold and pivoted at the center of the casting radius, to restrain the mold in an arc, is generally applicable to small machines.

In large machines, the driving lever becomes excessively long and, unless some additional structure is used to guide the mold along the prescribed arcuate path, the mold will not follow in a proper manner. The reciprocation equipment heretofore used in some applications comprises the usual driven cam and cam follower mounted to a lever which in turn is connected to the mold table. Such apparatus, however, has not proved to be entirely satisfactory.

The apparatus of the present invention, in contrast, comprises a continuous casting mold supported on a table that includes top and bottom separator members connected together by spaced apart arcuate-side rails that engage and follow an arcuate path established by adjustable rollers. The side rails are linked to a lever system that is powered to move the mold and mold table downwardly. The mold table is resiliently biased against springs so that, at the bottom of its downward stroke, the springs are compressed sufiiciently and they return the mold to the top of the stroke in a cyclical manner.

For a further understanding of the invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with the accompanying drawings which show, for the purpose of exemplification, a preferred embodiment of the invention. In the drawings:

FIG. 1 is a schematic elevational view of the apparatus of the invention;

FIG. 2 is a schematic elevational view, at an enlarged scale, of a portion of the apparatus of FIG. 1;

FIG. 3 is a sectional view along line III-IH of FIG. 2;

FIG. 3A is a view along line IIIA-IIIA of FIG. 2;

FIG. 4 is a schematic elevational view, at an enlarged scale, of another portion of the apparatus of FIG. 1; 'and FIG. 5 is a view along line V-V of FIG. 4.

The apparatus 11, illustrated in FIG. 1, comprises an arcuate continuous casting mold 13, a mold oscillating mechanism 15, anda cast strand guide and support structure 17.-

The continuous casting 'mold 13 is'of the open-end, flow-through type and has a generally straight cylindrical outer shell and an arcuate internal casting cavity wherein molten metal is received to form a" continuous strand or billet. The mold'13 is provided with the usual waterjacket cooling spaces and also a horizontal support shelf 19. Preferably, the horizontal support'she1f-19is water cooled and is adjustably mounted to a topseparator member 21 by means of a plurality of wedge key bolts 23.

The top separator member 21 is comprised generally of four end-connected rectangular side bars 25 (FIG.' 3') that form a rectangular opening through which the lower end portion of the arcuate casting mold 13 protrudes. The ends of two opposite parallel side bars 25 extend beyond the other interconnecting side members, and are slotted to receive rollers 27 that are journalled therein on pins 29 (FIG. 3A).

Beneath the top separator member 21, there are two spaced apart parallel side-frame members 31, 33, each of which has a generally trapezoidal profile in elevation (FIG. 1). Each side-frame member 31, 33 is fixed to a suitable supporting structure, such as an arrangement of I-beams 35 shown in FIG. 1, and the two spaced apart side-frame members 31, 33 are fixedly connected together by means of tie plates 37, 39 that may, of course, be connected to the side-frame members in any suitable manner, as by bolts or welding, or the like.

The side-frame members 31, 33 are each comprised of a trapezoidal shaped skeletal frame 40 that is covered on the outside by a bolted cover plate 41, 43. The top and bottom skeletal frame members 40 are each slotted, as at 45, 47 (FIG. 3), to pass therethrough a curved rail member 49, 51 having the same general radius of curvature as the casting cavity within the mold 13. Each curved rail 49, 51 has a tongue 53 projecting from the end for engaging a groove in the bars 25 comprising the top separator member 21, and the rails 49, 51 are fixed to the top separator member 21 by means of bolts 55 recessed in the side bars 25 (FIG. 2). In like manner, each curved rail 49, 51 is also tongue-mounted as at 57, and bolted as at 59, in a bottom separator member 61 that is substantially identical to the top separator member 21.

0f the two side rail members 49, 51, only the rail member 49 has, in each of its arcuate longitudinal edge surfaces, an elongate groove 63 for receiving a plurality of conventional oscillating cam followers 65. Each cam follower 65 is mounted in an eccentric cartridge on a shaft 67, and is provided with a self-locking nut 69 whereby the cam follower 65 may be adjusted to selectively position the rail member 49 with respect to the axis of both the casting mold 13 and the apron structure 17. The other rail member 51, however, does not have grooves in its arcuate edge surfaces. Similar cam followers (not shown) mounted on shafts 71 (FIG. 3A) are fixed in position by means of similar self-locking nuts 73, and these other cam followers simply ride on and engage the arcuate edge surfaces of the rail member 51, but do not operate in grooves in the arcuate rail member 51.

As shown in FIG. 2, each oscillating cam follower 65 is fastened to the side-frame members 31, 33 by means of bolts 75, but, of course, other suitable fastening means may be employed if preferred.

V The bottom separator member 61 is connected, adjacent each end, to adapting links 77 (FIG. 2) by means of pivot pins 79 journalled as at 81 to the separator member 61. The other end of each adapting link 77 is pivotally connected, as at 83 to one end of a lever 85 that forms a part of the mold oscillating mechanism 15. Thus, there are two spaced apart parallel levers 85, each of which is connected to a side rail (FIGS. 3 and 3A) by means of a link 77 and pins 79, 83. Each lever 85 also is keyed, as at 86, to a common shaft 87 that is journalled in bearings 89 that may be fixed inany suitable manner to the support structure 35. A single lever 90 is also keyed to theshaft 87 and extends in a direction away from, and generally parallel to, the levers 85. That is, the lever 90 extends toward the left as viewed in FIG. 1, while levers 85 .extend toward the right from the fixed shaft 87.

An hydraulic cylinder piston arrangement 91 ispi.v'- otally connected at 93 both to the lever 90, near the free end thereof, and to a fixed vertical support structure 95. The free end of the lever 90is also fitted with a slotted finger member (not shown) that cooperates with a conventional hydraulic control valve 97 mounted to a fixed support structure 99.

Hydraulic control valve'97 regulates the flow of fluid into and out of the expansion cylinder 91 and thus regulates the movement of the lever 90. It is to beunderstood, however, that in some applications the control valve 97 may be an electrical switch device that controls the flow of fluid to the expansion cylinder 91, if such type of apparatus be preferred.

Referring to FIG. 3A, the side-frame members 31, 33 are each provided with vertically arranged axial apertures 101, 103 in the top and bottom horizontal portions of the skeletal frame 40, and in the aperture 101 at the top of the skeletal frame 40 there is a bushing 105 in which a push rod 107 reciprocates.

The push rods 107 extend both above and below the top horizontal skeletal member 40; the upper portions engaging the rollers 27 while the bottom ends of the push rods 107 are each welded to a flange-like abutment 109. A pilot portion 111 on each lower end extends below the abutment 109 and mates in a hole 113 in another abut.- ment 115 of substantially the same size as the abutment 109. The abutment 115 is welded to the upper threaded end portion of a spring rod 117 that supports upper and lower spring retainers 119, 121, respectively.

A compression spring 123 encircles the spring rod 117 and cooperates with the upper and lower spring retainers 119, 121. The location of the upper spring retainer 119, relative to the spring rod 107, is determined by the location of a pair of lock nuts 125 threaded on the spring rod 117. The lower spring retainer 121, however, is not adjustable since it engages the lower horizontal skeletal frame member 40. The lower spring retainer 121 also is provided with a bushing 127 within which the lower end portion of the spring rod 117 reciprocates.

The lower end portion of the spring rod 117 has therethrough a transverse hole 129 that is alignable with holes 131 in the spring retainer 121 for use in assembling the apparatus 11. When assembling the apparatus 11, the spring 123 is compressed, in any suitable manner, until the hole 129 in the spring rod 117 is aligned with the holes 131; then, a pin (not shown) may be inserted through both sets of holes 129, 131 to keep and maintain the spring assembly in a slightly compressed form which can be easily handled and inserted into place. When the pin is later withdrawn, the spring 123 expands and the spring retainers 119, 121 assume the position shown inFIG. 3A. Suitable lugs, or a ring 133 on the end of the lower spring retainer 121, mates with a groove in the lower skeletal frame member 40 to keep and maintain the end of the lower spring retainer 121 in axial alignment with the hole 103 in the skeletal frame member 40. i

The mold support table 19 is preferably hollow and communicates withthe annular cooling fiuid'space in the mold 13, so that cooling fluid, entering the mold support table 19 through a conduit 135 (FIG. 2), circulates through the mold support table and the mold 13. There after, the fluid discharges from the mold table through drain conduits 137 that extend downwardly between the arcuate rail members 49, 51 (FIG. 3). To the lower end of each downwardly directed reciprocable drain conduit 137, there is connected, as by a pin 139, an arcuate drain conduit 141. The drain conduit 141 is disposed within a spray shield 143 that surrounds the lower end of the mold 13 and is disposed between the mold and the side frame members 131, 133. The lower end of the drain conduit 141 may be supported in any suitable manner (not shown) 1 l he spray shield 143 comprises an open ended shroud that has agenerally rectangular cross sectional, shape and an arcuate profile, as viewed in FIG. 2.. The spray shield 143 surrounds the lower end of the mold 13 and is supported at its bottom edge by bars 145 thatzare welded to the walls of the spray shield and engage the flange of an H-beam 147, or other suitable firm supporting structure. While the spray ,shield143 rests. on the H-beam 147,- the top of the shield 143 is free to float. betweenthe top horizontal bars of the. side-frame members 31, 33.

Within the spray shield 143, there is also a short length of apron structure 17 that is similar to the structure disclosed in my copending applicationSer. No. 544,908, filed Apr. 25, 1966. The apron structure 17 comprises, generally, arcuate. angle members 149 that supp rt pairs of rollers 151, 1 53 mounted for rotation in mutual perpendicular planes (FIG, 4), and the structure is supported by vertical aperturedside plates 155 that are fastened, as by bolts 157, to a fixed supporting frame structure. 159.

. As shown in FIG. 4, an opposed pair of rollers 161 are mounted to the bottom of the casting mold 13 to engage and guide a cast strand 163 as it emerges from the bottom of the mold 13. .In some applications two opposed pairs of such rollers 161 maybe used in order to reduce wear onthe mold.

In operation, molten metal 165 flows into the casting mold 13 from a tundish 167 located above the mold, and the mold 'is oscillated vertically along an arcuate path by the oscillating mechanism 15 to prevent the skin of the casting from sticking to the walls of the mold.

Fluid is introduced intothe expansion cylinder 91,,and,

. as the piston portion moves upwardly,.the lever 90 pivots 5 clockwise about the shaft 87. The levers 85, being keyed to the shaft 87, thus pivot clockwise and, acting through the links 77, urge downwardly the mold oscillatingassembly comprising: the top andbottom separators 21, 61 respectively; the arcuate side rails 49, 51; the mold table 19; and the mold'13. As this assembly moves downward, the rollers 27 depress the push rods 107, and the push rods 107, acting on the spring rods 117, compress the springs 123.

As the lever rotates clockwise during the downward portion of the stroke of the mold 13, the free end of the lever 90 trips the valve 97; the flow of fluid to the expansion cylinder 91 andthe downward movement of the mold cease. Duringthe downward portion of the mold movement, the springs 123. have become compressed by the action of the rollers 27 engaging the push rods 107 and spring rods 117. After the downward movement of the mold ceases, the mold is free to move upward again. At this moment, the springs 123 urge the separator-rails-mold assembly upward, and the lever 90 pivots counterclockwise. As the lever 90 pivots counterclockwise, it actuates the valve 97 again and once more fluid flows into the expansion cylinder 91 pivoting the lever 90 clockwise, while the assembly of the separators 21, 61, rails 49, 51, and mold 13, move do'wnward again.

Thusjthere is established c'yclical oscillatory movement of the mold 13; the stroke of which is established by a selected setting of the valve and valve operating mechanism 97.

The continuous cast strand 163 first engages, and is guided by, rollers 16]. fastened to the lower end of the casting mold, but laterthecontinuolYs cast strand engages the rollers 151,153 of the-shortfirst apron structure 17 and is guided thence inthe direction of the path of the principal apron structure17adifsposed below the spray shield 1,143; I I f A feature 'of 'the'pre'sent invention is thatiwhe'n the mold is urged downwardly under the influence of the expansion cylinder 91 and levers 9t), 85 ;and links77, the path described by the mold is predetermined by an appropriate setting of the adjustable cam followers '65 that engage the side rails 49, 51. Thus, the arcuate path described by the mold may become more nearly a true circular are that is readily established by the adjustable cam followers fixedly mounted to the mold table supporting side-frame members.

A feature of the present invention is that significantly less power is required to reciprocate the mold since rolling friction and not sliding friction exists between the cam followers and the guide rails.

A feature of the invention is the well guided and smoothly oscillating movement of the mold provided by the rolling cam followers inasmuch as there is a minimum of restriction due to expansion and contraction under wide temperature fluctuations. The result is that significantly less power is required to oscillate the mold along an arcuate path and there is significantly less chance for misalignment of the apparatus.

A feature of the invention is the shield around the cast strand in the region where it leaves the casting mold. The shield serves not only to confine the cooling water spray to the casting and prevent the spray from contacting the rollers and side rails, but also to prevent radiant heat from the cast strand from reaching and distorting the side rails, cam followers, andside-frame members. Such a shield is both a spray shield and a heat shield.

Although the invention has been described herein with a certain degree of particularity, it is understood that the present disclosure has been made only as an example and that various modifications and changes may be made within the scope of the invention as defined by the appended claims.

What is claim is:

1. Apparatus for use in the continuous casting of metal comprising:

(a) an open-end, flow-through mold wherein a continuous cast strand is formable;

(b) a mold table carrying said mold and including:

(i) a top separator member fixed to said mold table, and

(ii) a bottom separator member spaced apart from said top separator member, and

(iii) spaced apart arcuate guide rails fixed to said top and bottom separator members disposed on opposite sides of said cast strand;

(c) a fixed support adjacent said mold;

(d) a frame surounding said mold table and fixed to said support;

(e) opposed adjustably fixable spaced apart rollers mounted to said frames and disposed along parallel arcuate paths, said rollers cooperating with said arcuate rails and defining a path along which said rails move;

(f) a shaft j-ournalled to said fixed support;

(g) a lever journalled to said shaft and pivotally connected to the bottom separator;

(h) resilient bias means engaging said mold table and said support;

(i) means to pivot said lever and move said rails along the arcuate path defined by said rollers, said mold table and mold moving downwardly from an initial position and storing energy in said resilient biasing means; and

(j) means to release said stored energy whereby said mold moves upwardly to the initial position.

2.}The invention of claim '1 wherein:

(a) said resiliently .biasedmeansare springs.

3. The invention of claim 2 including:

(a) a heat" shield surrounding the lower portion of said mold and disposedbetween said cast 'stra'nd and said mails; and .e -(b) an arcuate apron. structure disposed .within said heat shield and mounted-adjacent-the lower end of said mold forreceiving' and supporting. said cast strand after it emergesifrom said mold.

4. The invention of. claim 3 including:

(a) an expansion cylinder pivotally connected to said lever and to said support as the means for pivoting said lever; and

(b) valve means actuatable by said lever as it pivots to control the movement of said lever and the vertical downward movement of said mold.

5. In apparatus for the continuous casting of a metal strand, the improvement comprising:

(a) an open-end, flow-through mold wherein metal flows and a continuous cast strand is formed;

(b)a mold table for carrying said mold on an arcuate path comprising:

(i) arcuate guide rails connected to said mold table and disposed on opposite sides of said cast strand, and

(ii) means cooperating with said guide rails defining arcuate paths along which said rails move; and

(c) means engaging said rails for reciprocating the same and said mold along said arcuate path.

6. The invention set forth in claim 5 wherein:

(a) said reciprocating means includes a pivotally mounted lever linked to said rails and to an expansion cylinder adapted to move said lever whereby said rails and said mold move downward;

(b) springs are resiliently biased against said mold whereby, as said mold moves downward under the influence of said lever, energy is stored in said springs; and

(c) means to release said stored energy in said springs whereby said rails and said mold are returned upward to the initial top position.

7. The invention set forth in claim 6 including:

(a) an arcuate apron structure mounted adjacent the lower end of said mold for receiving and supporting said continuous east strand after the same emerges from said mold; and

(b) shield means surrounding said cast strand and said apron structure and disposed between said apron structure and said guide rails whereby heat radiating from said cast strand is prevented from reaching said rails.

8. Vertical continuous casting mold-oscillating apparatus comprising:

(a) a reciprocable mold table carrying a vertical continuous casting mold;

(b) A frame fixedly supported adjacent said mold;

(c) adjustably fixable guide rollers mounted to said frame on opposite sides of said continuous cast strand;

(d) spaced apart guide rails fixed to said mold table and cooperating with said guide rollers;

(e) resilient bias means disposed between said frame and said mold table;

(f) a lever pivotally mounted to said frame and to said guide rails;

(g) means to pivot said lever for moving said mold downwardly from an initial top position along a path directed by the placement of said rollers which cooperate with and guide said rails, the downward movement of said mold table storing energy in said resilient bias means; and

(h) means to release said lever actuating means and release said stored energy for returning said mold 3,409,070 7 v 8 table and mold upwardly to said ini tialidp'position. 5 54. ReferencesCited r 9. The invention of claim 8 whereinzfi =1 .1 i r V UNITED STATES;I5ATENTS (a) said resilientbia's means are spnngsf andil -:(b)- said lever pivoting means'is fluidly-motivated; 2 1 la 1. fl s re a -r p 10."Iheinvention ofclaim-Qincludingr 5 3,166,803 1/1965 9 fii-fil (a) an apron structure disposed adjacent saidcasting 5 /1 311 256 Q1,

- mold for supporting said continuous casting as ithe 9/ 6J.;=Y gq 1- w same-emerges from said mold; and x i (b) ashield encompassing said'apron struotu're end a portion of said mold, said shield being disposed be- 10 sr-ANlqEAR Assista nt Ezcdminelr, tween said railsiand said casting. I P Q L 

5. IN APPARATUS FOR THE CONTINUOUS CASTING OF A METAL STRAND, THE IMPROVEMENT COMPRISING: (A) AN OPEN-END, FLOW-THROUGH MOLD WHEREIN METAL FLOWS AND A CONTINUOUS CAST STRAND IS FORMED; (B) A MOLD TABLE FOR CARRYING SAID MOLD ON AN ARCUATE PATH COMPRISING: (I) ARCUATE GUIDE RAILS CONNECTED TO SAID MOLD TABLE AND DISPOSED ON OPPOSITE SIDES OF SAID CAST STRAND, AND (II) MEANS COOPERATING WITH SAID GUIDE RAILS DEFINING ARCUATE PATHS ALONG WHICH SAID RAILS MOVE; AND (C) MEANS ENGAGING SAID RAILS FOR RECIPROCATING THE SAME AND SAME MOLD ALONG SAID ARCUATE PATH. 